Field of the Invention
The present invention relates to a wafer processing system that can continuously subject each wafer to a series of processes including a machining step and a testing step.
Description of the Related Art
In a semiconductor wafer machining step such as a cutting step or a grinding step, a plurality of wafers (e.g., 25 wafers) are loaded into a cassette that is transferred between apparatuses on a cassette-by-cassette basis by operators to perform various steps (refer, for example, to Japanese Patent Laid-Open No. 1997-027543). In a grinding apparatus, a plurality of wafers are placed into a cassette with a protective tape affixed to the front faces thereof. The wafers are taken out of the cassette by a wafer transfer robot for grinding on the rear faces thereof. After the grinding, the plurality of wafers are placed into a different cassette by the wafer transfer robot.
In a cutting apparatus, on the other hand, a plurality of wafers are placed into a cassette in the form of wafer units, each of which is supported by an annular frame via a dicing tape. The wafers are taken out of the cassette by a loading/unloading apparatus one at a time for cutting, followed by cleaning, after which the wafers are placed into the same cassette by the loading/unloading apparatus.